Method of making different colored marks with a single fluid



l i I l United States Patent METHOD OF MAKING DIFFERENT COLORED MARKS WITH A SINGLE FLUID Barrett K. Green, Dayton, Ohio, assignor to The National Cash Register Company, Dayton, Ohio, a corporation of Maryland No Drawing. Continuation of abandoned application Serial No. 60,405, November 16, 1948. This application May 28, 1952, Serial No. 290,556

3 Claims. (Cl. 117-45) This invention relates to a method of making difierent colored marks with a single fluid and more particularly pertains to a liquid containing an ink and a color-forming reactant to be used in conjunction with sensitized and unsensitized record material, said fluid, when applied to unsensitized record material, without visually perceptible delay making a permanently stable color mark thereon by reason of the intrinsic color of the ink, and, when applied to sensitized record material, without visually perceptible delay making a permanently stable differently colored mark thereon by reason of the intrinsic color of the ink blending with the color produced in the colorforming reactant on contact with the sensitized record material.

This is a continuation of my application Serial No. 60,405, filed November 16, 1948, now abandoned.

2,714,074 Patented July 26, 1955 hence, are free from the defects of air-oxidizable leuco Since it is withinthe purview of this invention to use ing, spotting, or printing. A fluid carrier for applying the fluid is described in my application Serial No. 60,642, filed November 18, 1948, and alp'orous printing member for applying the fluid is described in my application Serial No. 60,404, filed November 11, 1948. Said applications Serial No. 60,404 and Serial No. 60,642 have been abandoned after the filing of a continuation application, Serial No. 209,981, on February 8, 1951. However, I contemplate the use of my process in letter-press and offset printing, hand-stamping, stencilling, painting, and like operations.

A fluid is first prepared containing a selected ink and a selected color-forming reactant, and then the dualpurpose fluid is applied selectively to unsensitized or sensitized receiving material. The ink may be of either the dye or the pigment. type, and the color-forming reactant may be a liquid or a solid which is dissolved so as to form a fluid mixture with the ink. The ink, if it is itself a fluid, may be used as a solvent or vehicle for the color-forming reactant or vice versa. In any instance, it is proposed that the color-forming reactant will remain in its unreacted state in the fluid or as marks of dried fluid unless it comes into contact with the sensitized material.

Because the invention is primarily important in the field of record keeping, where the distinctiveness of the aminophenyl) 6-dime thylamino phthalide, having the two difierent colors must be maintained, it is important vat dyes, which are sometimes used in conjunction with inks in the so-called fraud-preventing inks, such as those described in United States Patent No. 2,068,204, which issued on the application of B, W. Smith.

As the process finds its most important use in printing, a preferred embodiment of the invention as employed in that art is disclosed, using as an example the application of the fluid to record material, sensitized in selected areas, by means of an ordinary rubber hand stamp having type faces of rubber or artificial rubber, which may be coated with the fluid in any manner, as by pressing the stamp against an absorbent pad previously: impregnated with the fluid. v

Therefore, it is an object of this invention to provide a method of making diflerent colored marks, color-stable in the presence of light or air, with a single fluid.

Another object of the invention is to provide such a method in which the ink color blends with the color formed by the color-forming reactant, on reaction, to produce a color distinctive from that of the ink and unreacted color-forming reactant.

With these and otherobjects in view, the invention will be described as embodied in a preferred and other forms, showing its utility and noveltyl In describing the preferred embodiment, the method will be assumed to be used in conjunction with paper having sensitized and unsensitized areas. "The s'ensitiz'a-j tion is" carried out by application to the paper of fine particles of attapulgite, sometimes known as Attapulg'us clay, which is white and ideally suited as a paper coating in the mannerthatother clays are ordinarily used. This attapulgite 'inay' be applied to the'paper by use of paper coating starch in'the following manner: Twenty per cent, by weight, of paper coating starch in water is cooked at 200 degrees Fahrenheit for fifteen minutes and, after cooling, adding to one part, by weight, of the cooked starch four parts, by weight, of a dispersion of one part, by weight, of attapulgite in three parts, by weight, of water. This coating material is applied to paper, on selected areas, at room temperature, and

dried. The recommended thickness of the coating, .0005 of an inch, may be varied considerably. The preferred fluid is made by dissolving three per cent, -by-weight, of crystal violet lactone, which is'3,3,bis(p-dimethyl structure and three per cent, byweight, of vthe red dye Sudan III, which is 9% per cen-t-., by weight, of chlorinated diphenyl of 48- per cent, by weight, chlorine contentv The fluidis then ready to be absorbed: in a stamp pad, transferred to the stamp, and applied by the stamp to sensitized or nnsensit-izedareas of the paper, as desired; This fluid is normally red and will make a reel print when applied By the stamp to unsensitized record material but will make a very dark purplish print when applied to record materialsensit-i'zed' by the attapulgite. The: red and the dark purplish prints appear without visually perceptible delay when the in'kis applied to the record material. Crystal violet lactone may he produced by a method described in United States Patent No: Re. 23,024, which issued on the application of Clyde S. Adams There'may'be substituted for the crystal violet lact'one of the preferred embodiment other color-forming react ants which are considered equivalents of that compound, which: have a normally colorless state, and which assome a color, without visuallyperceptible delay, when in adsorption contact with atta'pu'lgit'e'.

Amongthese substitutes may be mentioned 1. Malachite green lactone, which is 3,3 bis (p di methylaminophenyll phthalide, having thestructure producing a green color,

2'. The compound 3,3 bisp-diethylaminophenyl),-6- dimethylamino phthalidq. having: the structure itcliils producing a dark blue color,

3 The compound Mi chlers: H'ydrol, which is bis('pdimethylaminophenyl methanol, having the structure producing a dark blue color,

4. The methyl ether of Michlers Hydro], which is his (p-dimethylaminophenyl) methoxy-methane, having the structure (OHa)2N I NICHDV H a l (Lon;

producing a dark blue color,

5. The compound 3,3 bis(p diethylaminophenyl) phthalide,. having. the structure producing a blue-green color,

6. The compound 3,3 bis (p methylaminophenyl) phthalide, having the structure GHaHN- producing a: bright blue color,

7'. The compound 3,3' bis (p-ethylaminophenyl) phthalide, having the structure producing, a dark blue color,

8'; The compound. 3,3 bis'(p-n-dipropylaminophenyl) phthalide, having, the structure which is normally yellow but rjeacts'to produce a bluishgray color and may be used with red dye ink.

10. The compound o-hydroxybenzalacetophenone, having the structure v H v which normally is or a light yellow color and produces, on reaction, a reddish-yellow color, such being suitable for use with blue dye to produce a green mark on sensitized paper and a purple mark on unsensitized paper.

The above list is far from being exhaustive but gives a wide choice of color reactants.

In place of attapulgite, color reactants 1 to 8 react with halloysite, magnesium trisilicate, and sodium aluminum silicate zeolite material, all suitable for making recording surfaces and all to be considered equivalents of attapulgite. Color reactants 9 and 10, additionally, react with bentonite and halloysite. The sensitized surface may be prepared by binding such sensitizing material in any way, as by adhesives or paints which do not mask the surface of the particles, so that they remain available to the fluid-carried color-forming reactant applied thereto.

I consider as other equivalents of the color-reactant i'irystal violet lactone, in addition to those specifically recited, any color-reactant compound that may be carried in a liquid vehicle, which compound is color-stable in light or air in the uncolored or unreacted form in which it is present in the unapplied printing fluid, which is color-stable on unsensitized record material in the presence of light or air, but which will turn to a colored form on contact with record material sensitized as specified, without visually perceptible delay, and remain colorstable in the colored form in the presence of light or air. I do not consider compounds of the vat dye class disclosed in the before-mentioned United States Patent No. 2,068,204, which issued on the application of B. W. Smith, as equivalents of crystal violet lactone, because exposure of those vat dye compounds in the so-called leuco or unoxidized state to light and air results in their turning to the same colored oxidized form, whether they are on unsensitized record material or on sensitized record material. Moreover, the compounds mentioned in the aforesaid Smith patent will not form color on any of the oxidizing materials disclosed in said Smith patent without visually perceptible delay even in the presence of strong sunlight, the oxidization to the colored form taking at least several hours.

I consider as equivalents of the color-reactant attapulgite, in addition to those compounds and minerals specifically recited, solid particulate chemical compounds and minerals which, without visually perceptible delay, cause a color change in the color-reactant crystal violet lactone, or its equivalents in the printing fluid, on contact therewith, which are substantially inert as to record material, and which are substantially white or colorless.

The embodiments of the invention disclosed produce marks that usefully are color-stable to the aging influence of light and the atmosphere. The inks are stable in color on both the unsensitized and sensitized areas of the associated record material. The color reactant in the applied fluid is stable to light and atmospheric aging in the unreacted condition on the unsensitized portions of the record material and likewise stable in the reacted color condition on the sensitized portions of the record material.

While the action of the ink and color-forming reactant is best carried out when the ink is of the dye type which will not mask the color produced by the color-forming reactant, the use of pigments in the ink is contemplated if such are selected so as not to mask the color produced by the color-forming reactant material.

It will be apparent that the sensitized and unsensitized materials may be separate entities and not merely areas on a single unitary surface.

It will be obvious that the invention may be carried out by the use of other materials than those mentioned, and, therefore, the invention is claimed broadly.

What is claimed is:

1. The method of making, by use of a single marking fluid, marks of one color on unsensitized record material and marks of another color on: record material sensitized with particles of attapulgite, including the step of applying, according to the required configuration to form the marks, to the unsensitized record material and to the sensitized record material, as desired, a colored marking fluid including as a component thereof the normally substantially colorless color reactant 3,3 bis(p-dimethylaminophenyl) G-dimethylamino phthalide, having the structure and which is stable to light or air on the unsensitized record material, but turns dark blue, without visually perceptible delay, upon coming into contact with record material sensitized with attapulgite, whereby marks made on unsensitized record material are distinctively difierent in color from marks made on sensitized record material. 2. The method of printing data in ditferent colors in different areas on record material, with a single fluid, so that data printed in one area is diflerent in color from that printed in another area which has been sensitized by having had applied thereto particles of attapulgite, including the steps of printing data in the sensitized area and in the unsensitized area, as desired, with a colored marking fluid containing, as one ingredient the colorless color-reactant, 3,3 bis(p-dimethylaminophenyl) 6-dimethylamino phthalide, having the structure (CHahN N(CHs)z N (CH3):

and which is normally substantially colorless and stable in light or air on the unsensitized area of the record material but which turns dark blue, without visually perceptible delay, on coming into contact with the area of the record material sensitized with attapulgite, whereby marks made on sensitized areas are distinctively colored differently from marks made on unsensitized areas.

3. The method of making marks of different color on a single piece of record material, by use of a single marking fluid, including the steps of preparing markingfluid-receiving record material by sensitizing selected areas of the record material by applying thereto particles of attapulgite; preparing a marking fluid having a normal color and having therein a substantially colorless fluid vehicle in which has been dispersed 3,3 bis(p-dimethylaminophenyl) 6-dimethy1amino phthalide, having the and selectively applying the fluid to sensitized and unsensistructure 7 tiied ziras 6f the fc'ofd material, as desired.

References Cited in the file of this patent UNITED STATES PATENTS 2,068,204 Smith Jan. 19, 1927 2,337,737 Champion Dec. 28, 1943 2,348,128 Groak May 2, 1944 10 2,474,084 Adams June 2 1, 1949 2,548,366 Gfen Apr. 10, 1951 HahN 

3. THE METHOD OF MAKING MARKS OF DIFFERENT COLOR ON A SINGLE PIECE OF RECORD MATERIAL, BY USE OF A SINGLE MARKING FLUID, INCLUDING THE STEPS OF PREPARING MARKING FLUID-RECEIVING RECORD MATERIAL BY SENSITIZING SELECTED AREAS OF THE RECORD MATERIAL BY APPLYING THERETO PARTICLES OF ATTAPULGITE; PREPARING A MARKING FLUID HAVING A NORMAL COLOR AND HAVING THEREIN A SUBSTANTIALLY COLORLESS FLUID VEHICLE IN WHICH HAS BEEN DISPERSED 3,3 BIS(P-DIMETHYLAMINOPHENYL) 6-DIMETHYLAMINO PHTHALIDE, HAVING THE STRUCTURE 